1. Field of the Invention
The present invention relates to a method of filling a container, preferably containing at least one concentrate, with the concentrate being formed such that it forms at least one liquid concentrate or a part of a liquid concentrate on its solution in or its dilution with a liquid, preferably water, said liquid concentrate or part of a liquid concentrate being suitable for preparing at least one dialysis solution, and with the filling of the container taking place by means of the balance chamber system of a dialyzer which has chambers from which the liquid is conveyed into the container in the form of repeating cycles.
2. Description of Related Art
It is known from the prior art to prepare a dialysis solution with the aid of dry concentrates. These dry concentrates contain different salts, for example, which are brought into solution by water. The concentrated solution prepared in this manner is used to prepare a dialysis solution, optionally with further concentrates and water which is ready to use and which is then used within the framework of a dialysis process.
To introduce water into the container containing the dry concentrate, a pump or also the balance chamber system of the dialyzer, can be used, for example. Such a procedure as well as a container containing dry concentrate is known, for example, from DE 10 2011 106 248 A1. A balance chamber system serves the control of the volume supplied to the dialysis machine and led off from the dialysis machine during the carrying out of a dialysis treatment.
The balance chamber system typically comprises two rigid chambers of a fixed volume which are each separated by a movable separation membrane into a compartment for fresh dialysis solution (also called “fresh water compartment” in the following) which is conducted toward the dialysis machine during the treatment and into a compartment for consumed dialysis solution (also called “used water compartment”) which flows from the dialysis machine into the chamber during the treatment. Liquid, namely fresh dialysis solution from a source for the dialysis solution, is conveyed from both chambers into the dialysis machine and consumed dialysis solution is conveyed from the dialysis machine into the waste during the treatment.
Due to the movement of the separation membrane in the chamber and the actuation of valves which are arranged upstream and downstream of the chambers, the volume conveyed away from the dialysis machine is identical to the volume conveyed toward the dialysis machine.
If such a balancing system of the dialyzer is used for filling a concentrate container, no consumed dialysis solution is introduced from the dialysis solution into the balancing system.
On the filling of the container by means of the chambers of the balance chamber system, care must be taken that the total filling volume corresponds to the specifications so that it is ensured that the desired filling quantity is achieved or the dry concentrate is actually dissolved or the correct mixing ratio is maintained and thus the desired concentrations of the dissolved substances in the prepared liquid concentrate are achieved.
If the total filling volume, i.e. the conveyed liquid volume conveyed into the container in total is determined from the number of filling cycles and the conveyed filling volume per cycle, it must thus be ensured that the filling volume conveyed per cycle corresponds to the specifications or is known. If a leak or leakage occurs, for example in a valve which closes a chamber of the balance chamber system, this would have the consequence that the filling volume supplied to the container per cycle and thus the total filling volume does not correspond to the desired value, which is naturally unwanted. For the dissolving of the granulate located in the container is an important aspect in concentrate preparation. Measurements have shown that the granulate of typical containers completely dissolves from a filling volume of 3.6 l. To ensure this filling volume, limit values, i.e. tolerances, can be fixed at a level of 50 μl/switchover, for example, which may not be exceeded.
If this limit value of the filling volume is nevertheless exceeded, e.g. due to a leakage, this would under certain circumstances have the consequence of an insufficient dissolving of the dry concentrate and thus concentrations of the substances in the liquid concentrate which lie outside the comparatively narrow specification limits. The same applies accordingly on the use of liquid concentrates. It must also be ensured with these that the solution obtained by mixing has the desired concentrations.
An apparatus for leak recognition of the movable separation wall of a membrane apparatus for conveying an infusion solution having an optical sensor is described in U.S. Pat. No. 4,431,425. DE 197 28 280 C1 discloses an apparatus for conveying liquids for a medical treatment apparatus in which the number of pressures pulses over time is monitored.
The pressure holding tests of the valves of the balance chamber system and of the connected line system carried out as standard are not sensitive enough so that a sensitively reacting monitoring process for the leak tightness of the system is necessary.